TV-Series
Description
Ranze Nanaboshi (alternatively Rayne Nanahoshi in certain regions) holds the position of vice-president within the student council at Goha 7th Elementary School. She supports council president Gavin Sogetsu in upholding school regulations and ensuring order. Ranze and her twin brother, Rinnosuke Nanahoshi, descend from a lineage serving the Sogetsu clan for generations as ninja retainers.

She possesses fair skin, hazel eyes, and blonde hair styled in a distinctive, severe bouffant similar to her brother's. Rectangular spectacles with a blue half-frame contribute to her studious look. Her standard outfit includes a teal waistcoat over a gray sleeveless corset-like top, a white shirt with a red tie, a gray miniskirt, knee-length blue socks, and brown slip-on shoes. For duties related to the Sogetsu Style or tasks such as cooking, she wears traditional Kuroko stagehand attire: a charcoal veil, gray top and pants, black tunic and shoes, and a blue sash.

Ranze demonstrates intense devotion to her responsibilities and Gavin, sometimes acting according to her own judgment regardless of his stated wishes. Early on, she attempts to dissuade Gavin from Rush Duels and association with Yuga Ohdo's circle. She exhibits a snarky, critical attitude, particularly when assisting Romin Kassidy with cooking. Despite her disciplined exterior, Ranze harbors a tendency for rapid, intense romantic infatuations. Secretly observing Yuga to evaluate his suitability as Gavin's friend leads to her developing feelings for him, which she consistently denies. Her brother later reveals she maintains 75 love diaries documenting past crushes. When infatuated, she misinterprets mundane interactions as romantic declarations, a trait termed "Rayne Eyes" by others; this delusional behavior occasionally skews her perception, casting her as a cloudcuckoolander.

Ranze undergoes significant development. Initially, she and Rinnosuke function as near-identical enforcers for Gavin, but their personalities diverge. Ranze grows more cynical and questions Gavin's leadership, especially during the Goha 6th Elementary arc. Her infatuation with Galient Tazaki prompts her to duel against Yuga's group on Galient's behalf, marking a departure from her loyalty to Gavin. Later, she experiences a crisis of faith, imagines herself as a protagonist, and decides to leave Gavin's service to forge her own path. She temporarily defects to serve Neiru Saionji, becoming an unwelcome presence he repeatedly tries to dismiss. After Gavin defeats Neiru in a duel, showcasing his growth, Ranze returns to his side, reaffirming her commitment.

As a duelist, Ranze employs a Plant-type "Flower Fang" deck focused on swarm tactics and piercing damage. Her strategy involves setting multiple monsters defensively and waiting for an opportunity to strike for victory. Key monsters include Flowerfang Beauty Gekka, Flowerfang Kunoichi Etranzer, Flowerfang Oni Yuri, and Flowerfang Orchid Lion Gajuumaru. Spells and traps like Flowerfang Spores, Flowerfang Orchid Dance, Greater Piercing!!, and Flowerfang Shadow Strike support her aggressive playstyle. Her duel record includes losses to Galient Tazaki and Gavin Sogetsu, and a draw against Rinnosuke.

Her relationship with Rinnosuke evolves from initial uniformity to nuanced sibling dynamics. While both share stoic professionalism and loyalty to Gavin, Ranze proves more prone to romantic delusions and defiance. Their duel in episode 36 ends in a draw via mutual destruction, symbolizing unresolved tensions. Rinnosuke occasionally acts as an annoying younger sibling, teasing Ranze about her crushes, but also intervenes to ground her during extreme delusional episodes.